Why your sister said that?
I don't know....but I know this...
I can vacuum lead and asbestos with my Kirby's, my Hoovers, my Eureka's, my Lewyt...I can even vacuum lead and asbestos with my own lungs and a soda straw.
Should I be doing this is the question. And the answer is no. It's not just about sucking it all up into a container. It's also about displacement of the hazardous material via shoes, equipment, agitation of the air, etc., while doing the work.
Here in St. Louis, you'll sometimes come across an old building that looks like it's shrink wrapped. In actuality, it's being "tented" for control of hazardous material. Sometimes for extermination of vermin and insects, sometimes for containment and removal of asbestos, lead, uranium, etc. (Yes, uranium -- Malinkrodt Chemical did certain Manhattan Project work here in St. Louis as well as Weldon Springs, MO)
It's not just a matter of scraping it up and vacuuming it away. And like those demonstration vacuum tests -- some is always left behind. There are procedures, compounds and equipment to get this left behind hazard.
Like you said...."leave it 2 the pros."